At a glance
Size Exclusion Chromatography
ScopeSize-based
CAPEX$150k-$1M
Best forBuffer exchange, aggregate removal
vs
Ultrafiltration
Scope1-100 kDa MWCO
CAPEX$100k-$600k
Best forProtein concentration & buffer exchange
Decision criteria
| Criterion | Size Exclusion Chromatography | Ultrafiltration | Verdict |
|---|---|---|---|
| Separation principle | Buffer exchange, aggregate removal | Protein concentration & buffer exchange | Diffusive vs convective transport |
| Throughput / scale | Low (1-100 L/hr) | High (100-50,000 L/hr) | UF much higher |
| Capital cost | $150k-$1M | $100k-$600k | UF lower |
| Operating cost | High (slow, dilution) | Low | UF much cheaper |
| Product purity ceiling | Resolves close-MW species | Sharp cutoff only | SEC for resolution |
Quick verdict
UF for production buffer exchange. SEC for analytical resolution or final-step aggregate removal.
Rule of thumb: Manufacturing scale? UF. Analytics or final polish where dilution doesn't matter? SEC.
Frequently Asked Questions
When should I choose Size Exclusion Chromatography over Ultrafiltration?
Use SEC for analytical buffer exchange, aggregate sizing, and final formulation polishing where dilution is acceptable.
When should I choose Ultrafiltration over Size Exclusion Chromatography?
Use UF/DF for manufacturing-scale buffer exchange — orders of magnitude faster and cheaper than SEC, no dilution penalty.
Can these two techniques be used together?
SEC for analytics, UF for manufacturing. They're almost never in series in a production process.
Which has lower OPEX at scale?
SEC has poor productivity (~10x lower) and dilutes the product 2-5x. UF concentrates while exchanging buffer.
Read more on each technique
Try both in your flowsheet
Build a process with each option side by side and compare yield, purity, and cost.
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